There is a national interest in the discovery of alternative sources of fuels and chemicals, other than from petroleum resources. As the public discussion concerning the availability of petroleum resources and the need for alternative sources continues, government mandates will require transportation fuels to include, at least in part, hydrocarbons derived from sources besides petroleum. As such, there is a need to develop alternative sources for hydrocarbons useful for producing fuels and chemicals.
One possible alternative source of hydrocarbons for producing fuels and chemicals is widely available so called “biomass”, such as for example, lignocelluloses, starches, vegetable oils, algaes, and etc. It is also known that solid biomass such as the low cost and widely available lignocelluloses can be converted to liquid biocrude via acid hydrolysis process, pyrolysis process, liquefaction process, gasification and/or many other processes. The biocrude content various depend upon the type of the biomass and the type of conversion process being used. For example, the biocrude can be tars, acids, chars, alcohols, aldehydes, esters, ketone, aromatics and etc. if the biocrude are produced by pyrolysis of lignocelluloses; the biocrude can be monomer sugar units such as C5 or C6 sugars if the biocrude is produced by hydrolysis of lignocelluloses.
Biomass derived biocrude typically will need to be upgraded if it is to be used as transportation fuels such as diesel and gasoline. However, often times, the biomass derived biocrude contains significant amount of metal impurities (e.g. Na, K, Ca, Mg, and etc), which can have detrimental effects in the upgrading process, especially when a catalytic process is used for the upgrading process. For example, it can cause catalyst deactivation and plugging of the reactor catalyst bed. The biomass-derived biocrude, especially pyrolysis oil, may contain high molecular weight components. These materials also cause plugging and fouling of the catalyst bed because they are too large to react in the pores of the catalyst.
As such, it is desirable to develop a process for removing metal impurities and high molecular weight components from biomass derived biocrude to prevent potential catalyst poisoning and catalyst bed plugging in biocrude-to-transportation fuel upgrading process.